Adults who drink at least one sugar-sweetened drink a day
are slightly more likely to develop kidney stones than people who rarely imbibe
them, according to a new study.
While the recommendation for kidney stone prevention has
been to drink a lot of fluids, the study suggests that it's not just the amount
of fluid but the type of drink that also matters. Dr Gary Curhan, the senior
author of the study, said patients often ask for dietary advice to help prevent
While the recommendation has been to drink plenty of fluids,
Curhan said, patients often ask, "what should I drink? There's a lot of
lore out there."To see whether the type of beverage might matter, Curhan,
of the Channing Division of Network Medicine at Brigham and Women's Hospital,
and his colleagues collected data from three massive surveys of nearly 200 000
Diet and lifestyle
The questionnaires surveyed participants every two to four
years and asked about diet, lifestyle and health, including how much they drank
certain beverages and whether they developed kidney stones. None of the people
in the study had kidney stones at the start.
They found that 159 out of every 100 000 people who drank a
sugar-sweetened non-cola beverage, such as clear soda, less than once a week
developed kidney stones, compared to 306 out of every 100 000 who drank soda
daily. After accounting for other factors, that translated to a 33% greater
chance of developing kidney stones.
Frequent punch drinkers also had an 18% higher chance of
developing kidney stones. For every 100 000 people who drank punch at least every
day, 226 developed kidney stones, compared to 158 out of every 100 000
participants who had punch less than once a week. Curhan said that while the
numbers of people developing kidney stones in each group are not enormously
different, the increased risk spread across an entire population is quite big.
"Sodas are so commonly used that even though the
absolute rate doesn't look that different, if there's a huge number of people
consuming it, then the magnitude on the public health can be quite
substantial," Curhan told Reuters Health. Other drinks, such as coffee,
tea, wine, beer and orange juice were tied to a lower risk of developing kidney
Other beverages and kidney stones
For instance, 205 out of every 100 000 people who rarely
drank coffee developed kidney stones, compared to 137 out of every 100 000
people who drank it daily. Just 96 out of every 100 000 people who drank red
wine daily developed kidney stones, while 174 out of every 100 000 people who
drank red wine less than once a week developed kidney stones.
Curhan's study, published in the Clinical Journal of the
American Society of Nephrology, follows others showing a link between stones
and fructose, non-dairy calcium, vitamin C supplements and other factors. The
new study doesn't prove cause-and-effect between certain drinks and kidney
stones, but it's possible that sugar could be involved, Curhan said, because it
might play a role in how the body handles calcium.
Another possibility is that sugary drinks might be
contributing to obesity, and obesity is also tied to a higher kidney stone
risk, said Dr Elaine Worcester, a professor at the University of Chicago, who
was not part of the study. Despite the lack of proof of a cause-effect
relationship, Worcester said "these kinds of studies are the best we have
to give advice to our patients."